The proposed research project is concerned with the morphological and physiological features of the lymphatic capillaries and the role of this system under normal physiological conditions as well as during the inflammatory response. A detailed ultrastructural investigation of the lymphatic capillaries is being undertaken in an effort to provide information that will further our understanding of the topographic relation of the lymphatic vascular system to the surrounding connective tissue area and the blood vascular system. The removal of interstitial fluids by the lymphatic capillaries is being investigated by following the progress of vital dyes and colloidal substances after interstitial injections. Studies are being carried out to determine the origin of serous fluids and cells and their subsequent removal by the lymphatic vascular system. Such studies will provide information that will further our understanding of the processes involved in the transfer of interstitial fluids and cells including the removal of cancerous cells by the lymphatic system.